summaryrefslogtreecommitdiffstats
path: root/drivers/thunderbolt/retimer.c
blob: 9cc28197dbc45f7e6912ac43fc01d40fe5a80027 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
// SPDX-License-Identifier: GPL-2.0
/*
 * Thunderbolt/USB4 retimer support.
 *
 * Copyright (C) 2020, Intel Corporation
 * Authors: Kranthi Kuntala <kranthi.kuntala@intel.com>
 *	    Mika Westerberg <mika.westerberg@linux.intel.com>
 */

#include <linux/delay.h>
#include <linux/pm_runtime.h>
#include <linux/sched/signal.h>

#include "sb_regs.h"
#include "tb.h"

#define TB_MAX_RETIMER_INDEX	6

/**
 * tb_retimer_nvm_read() - Read contents of retimer NVM
 * @rt: Retimer device
 * @address: NVM address (in bytes) to start reading
 * @buf: Data read from NVM is stored here
 * @size: Number of bytes to read
 *
 * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
 * read was successful and negative errno in case of failure.
 */
int tb_retimer_nvm_read(struct tb_retimer *rt, unsigned int address, void *buf,
			size_t size)
{
	return usb4_port_retimer_nvm_read(rt->port, rt->index, address, buf, size);
}

static int nvm_read(void *priv, unsigned int offset, void *val, size_t bytes)
{
	struct tb_nvm *nvm = priv;
	struct tb_retimer *rt = tb_to_retimer(nvm->dev);
	int ret;

	pm_runtime_get_sync(&rt->dev);

	if (!mutex_trylock(&rt->tb->lock)) {
		ret = restart_syscall();
		goto out;
	}

	ret = tb_retimer_nvm_read(rt, offset, val, bytes);
	mutex_unlock(&rt->tb->lock);

out:
	pm_runtime_mark_last_busy(&rt->dev);
	pm_runtime_put_autosuspend(&rt->dev);

	return ret;
}

static int nvm_write(void *priv, unsigned int offset, void *val, size_t bytes)
{
	struct tb_nvm *nvm = priv;
	struct tb_retimer *rt = tb_to_retimer(nvm->dev);
	int ret = 0;

	if (!mutex_trylock(&rt->tb->lock))
		return restart_syscall();

	ret = tb_nvm_write_buf(nvm, offset, val, bytes);
	mutex_unlock(&rt->tb->lock);

	return ret;
}

static int tb_retimer_nvm_add(struct tb_retimer *rt)
{
	struct tb_nvm *nvm;
	int ret;

	nvm = tb_nvm_alloc(&rt->dev);
	if (IS_ERR(nvm)) {
		ret = PTR_ERR(nvm) == -EOPNOTSUPP ? 0 : PTR_ERR(nvm);
		goto err_nvm;
	}

	ret = tb_nvm_read_version(nvm);
	if (ret)
		goto err_nvm;

	ret = tb_nvm_add_active(nvm, nvm_read);
	if (ret)
		goto err_nvm;

	ret = tb_nvm_add_non_active(nvm, nvm_write);
	if (ret)
		goto err_nvm;

	rt->nvm = nvm;
	return 0;

err_nvm:
	dev_dbg(&rt->dev, "NVM upgrade disabled\n");
	if (!IS_ERR(nvm))
		tb_nvm_free(nvm);

	return ret;
}

static int tb_retimer_nvm_validate_and_write(struct tb_retimer *rt)
{
	unsigned int image_size;
	const u8 *buf;
	int ret;

	ret = tb_nvm_validate(rt->nvm);
	if (ret)
		return ret;

	buf = rt->nvm->buf_data_start;
	image_size = rt->nvm->buf_data_size;

	ret = usb4_port_retimer_nvm_write(rt->port, rt->index, 0, buf,
					 image_size);
	if (ret)
		return ret;

	rt->nvm->flushed = true;
	return 0;
}

static int tb_retimer_nvm_authenticate(struct tb_retimer *rt, bool auth_only)
{
	u32 status;
	int ret;

	if (auth_only) {
		ret = usb4_port_retimer_nvm_set_offset(rt->port, rt->index, 0);
		if (ret)
			return ret;
	}

	ret = usb4_port_retimer_nvm_authenticate(rt->port, rt->index);
	if (ret)
		return ret;

	usleep_range(100, 150);

	/*
	 * Check the status now if we still can access the retimer. It
	 * is expected that the below fails.
	 */
	ret = usb4_port_retimer_nvm_authenticate_status(rt->port, rt->index,
							&status);
	if (!ret) {
		rt->auth_status = status;
		return status ? -EINVAL : 0;
	}

	return 0;
}

static ssize_t device_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct tb_retimer *rt = tb_to_retimer(dev);

	return sysfs_emit(buf, "%#x\n", rt->device);
}
static DEVICE_ATTR_RO(device);

static ssize_t nvm_authenticate_show(struct device *dev,
	struct device_attribute *attr, char *buf)
{
	struct tb_retimer *rt = tb_to_retimer(dev);
	int ret;

	if (!mutex_trylock(&rt->tb->lock))
		return restart_syscall();

	if (!rt->nvm)
		ret = -EAGAIN;
	else if (rt->no_nvm_upgrade)
		ret = -EOPNOTSUPP;
	else
		ret = sysfs_emit(buf, "%#x\n", rt->auth_status);

	mutex_unlock(&rt->tb->lock);

	return ret;
}

static void tb_retimer_set_inbound_sbtx(struct tb_port *port)
{
	int i;

	for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++)
		usb4_port_retimer_set_inbound_sbtx(port, i);
}

static void tb_retimer_unset_inbound_sbtx(struct tb_port *port)
{
	int i;

	for (i = TB_MAX_RETIMER_INDEX; i >= 1; i--)
		usb4_port_retimer_unset_inbound_sbtx(port, i);
}

static ssize_t nvm_authenticate_store(struct device *dev,
	struct device_attribute *attr, const char *buf, size_t count)
{
	struct tb_retimer *rt = tb_to_retimer(dev);
	int val, ret;

	pm_runtime_get_sync(&rt->dev);

	if (!mutex_trylock(&rt->tb->lock)) {
		ret = restart_syscall();
		goto exit_rpm;
	}

	if (!rt->nvm) {
		ret = -EAGAIN;
		goto exit_unlock;
	}

	ret = kstrtoint(buf, 10, &val);
	if (ret)
		goto exit_unlock;

	/* Always clear status */
	rt->auth_status = 0;

	if (val) {
		tb_retimer_set_inbound_sbtx(rt->port);
		if (val == AUTHENTICATE_ONLY) {
			ret = tb_retimer_nvm_authenticate(rt, true);
		} else {
			if (!rt->nvm->flushed) {
				if (!rt->nvm->buf) {
					ret = -EINVAL;
					goto exit_unlock;
				}

				ret = tb_retimer_nvm_validate_and_write(rt);
				if (ret || val == WRITE_ONLY)
					goto exit_unlock;
			}
			if (val == WRITE_AND_AUTHENTICATE)
				ret = tb_retimer_nvm_authenticate(rt, false);
		}
	}

exit_unlock:
	tb_retimer_unset_inbound_sbtx(rt->port);
	mutex_unlock(&rt->tb->lock);
exit_rpm:
	pm_runtime_mark_last_busy(&rt->dev);
	pm_runtime_put_autosuspend(&rt->dev);

	if (ret)
		return ret;
	return count;
}
static DEVICE_ATTR_RW(nvm_authenticate);

static ssize_t nvm_version_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct tb_retimer *rt = tb_to_retimer(dev);
	int ret;

	if (!mutex_trylock(&rt->tb->lock))
		return restart_syscall();

	if (!rt->nvm)
		ret = -EAGAIN;
	else
		ret = sysfs_emit(buf, "%x.%x\n", rt->nvm->major, rt->nvm->minor);

	mutex_unlock(&rt->tb->lock);
	return ret;
}
static DEVICE_ATTR_RO(nvm_version);

static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct tb_retimer *rt = tb_to_retimer(dev);

	return sysfs_emit(buf, "%#x\n", rt->vendor);
}
static DEVICE_ATTR_RO(vendor);

static struct attribute *retimer_attrs[] = {
	&dev_attr_device.attr,
	&dev_attr_nvm_authenticate.attr,
	&dev_attr_nvm_version.attr,
	&dev_attr_vendor.attr,
	NULL
};

static const struct attribute_group retimer_group = {
	.attrs = retimer_attrs,
};

static const struct attribute_group *retimer_groups[] = {
	&retimer_group,
	NULL
};

static void tb_retimer_release(struct device *dev)
{
	struct tb_retimer *rt = tb_to_retimer(dev);

	kfree(rt);
}

struct device_type tb_retimer_type = {
	.name = "thunderbolt_retimer",
	.groups = retimer_groups,
	.release = tb_retimer_release,
};

static int tb_retimer_add(struct tb_port *port, u8 index, u32 auth_status)
{
	struct tb_retimer *rt;
	u32 vendor, device;
	int ret;

	ret = usb4_port_retimer_read(port, index, USB4_SB_VENDOR_ID, &vendor,
				     sizeof(vendor));
	if (ret) {
		if (ret != -ENODEV)
			tb_port_warn(port, "failed read retimer VendorId: %d\n", ret);
		return ret;
	}

	ret = usb4_port_retimer_read(port, index, USB4_SB_PRODUCT_ID, &device,
				     sizeof(device));
	if (ret) {
		if (ret != -ENODEV)
			tb_port_warn(port, "failed read retimer ProductId: %d\n", ret);
		return ret;
	}

	if (vendor != PCI_VENDOR_ID_INTEL && vendor != 0x8087) {
		tb_port_info(port, "retimer NVM format of vendor %#x is not supported\n",
			     vendor);
		return -EOPNOTSUPP;
	}

	/*
	 * Check that it supports NVM operations. If not then don't add
	 * the device at all.
	 */
	ret = usb4_port_retimer_nvm_sector_size(port, index);
	if (ret < 0)
		return ret;

	rt = kzalloc(sizeof(*rt), GFP_KERNEL);
	if (!rt)
		return -ENOMEM;

	rt->index = index;
	rt->vendor = vendor;
	rt->device = device;
	rt->auth_status = auth_status;
	rt->port = port;
	rt->tb = port->sw->tb;

	rt->dev.parent = &port->usb4->dev;
	rt->dev.bus = &tb_bus_type;
	rt->dev.type = &tb_retimer_type;
	dev_set_name(&rt->dev, "%s:%u.%u", dev_name(&port->sw->dev),
		     port->port, index);

	ret = device_register(&rt->dev);
	if (ret) {
		dev_err(&rt->dev, "failed to register retimer: %d\n", ret);
		put_device(&rt->dev);
		return ret;
	}

	ret = tb_retimer_nvm_add(rt);
	if (ret) {
		dev_err(&rt->dev, "failed to add NVM devices: %d\n", ret);
		device_unregister(&rt->dev);
		return ret;
	}

	dev_info(&rt->dev, "new retimer found, vendor=%#x device=%#x\n",
		 rt->vendor, rt->device);

	pm_runtime_no_callbacks(&rt->dev);
	pm_runtime_set_active(&rt->dev);
	pm_runtime_enable(&rt->dev);
	pm_runtime_set_autosuspend_delay(&rt->dev, TB_AUTOSUSPEND_DELAY);
	pm_runtime_mark_last_busy(&rt->dev);
	pm_runtime_use_autosuspend(&rt->dev);

	return 0;
}

static void tb_retimer_remove(struct tb_retimer *rt)
{
	dev_info(&rt->dev, "retimer disconnected\n");
	tb_nvm_free(rt->nvm);
	device_unregister(&rt->dev);
}

struct tb_retimer_lookup {
	const struct tb_port *port;
	u8 index;
};

static int retimer_match(struct device *dev, void *data)
{
	const struct tb_retimer_lookup *lookup = data;
	struct tb_retimer *rt = tb_to_retimer(dev);

	return rt && rt->port == lookup->port && rt->index == lookup->index;
}

static struct tb_retimer *tb_port_find_retimer(struct tb_port *port, u8 index)
{
	struct tb_retimer_lookup lookup = { .port = port, .index = index };
	struct device *dev;

	dev = device_find_child(&port->usb4->dev, &lookup, retimer_match);
	if (dev)
		return tb_to_retimer(dev);

	return NULL;
}

/**
 * tb_retimer_scan() - Scan for on-board retimers under port
 * @port: USB4 port to scan
 * @add: If true also registers found retimers
 *
 * Brings the sideband into a state where retimers can be accessed.
 * Then Tries to enumerate on-board retimers connected to @port. Found
 * retimers are registered as children of @port if @add is set.  Does
 * not scan for cable retimers for now.
 */
int tb_retimer_scan(struct tb_port *port, bool add)
{
	u32 status[TB_MAX_RETIMER_INDEX + 1] = {};
	int ret, i, last_idx = 0;

	/*
	 * Send broadcast RT to make sure retimer indices facing this
	 * port are set.
	 */
	ret = usb4_port_enumerate_retimers(port);
	if (ret)
		return ret;

	/*
	 * Enable sideband channel for each retimer. We can do this
	 * regardless whether there is device connected or not.
	 */
	tb_retimer_set_inbound_sbtx(port);

	/*
	 * Before doing anything else, read the authentication status.
	 * If the retimer has it set, store it for the new retimer
	 * device instance.
	 */
	for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++)
		usb4_port_retimer_nvm_authenticate_status(port, i, &status[i]);

	for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++) {
		/*
		 * Last retimer is true only for the last on-board
		 * retimer (the one connected directly to the Type-C
		 * port).
		 */
		ret = usb4_port_retimer_is_last(port, i);
		if (ret > 0)
			last_idx = i;
		else if (ret < 0)
			break;
	}

	tb_retimer_unset_inbound_sbtx(port);

	if (!last_idx)
		return 0;

	/* Add on-board retimers if they do not exist already */
	ret = 0;
	for (i = 1; i <= last_idx; i++) {
		struct tb_retimer *rt;

		rt = tb_port_find_retimer(port, i);
		if (rt) {
			put_device(&rt->dev);
		} else if (add) {
			ret = tb_retimer_add(port, i, status[i]);
			if (ret && ret != -EOPNOTSUPP)
				break;
		}
	}

	return ret;
}

static int remove_retimer(struct device *dev, void *data)
{
	struct tb_retimer *rt = tb_to_retimer(dev);
	struct tb_port *port = data;

	if (rt && rt->port == port)
		tb_retimer_remove(rt);
	return 0;
}

/**
 * tb_retimer_remove_all() - Remove all retimers under port
 * @port: USB4 port whose retimers to remove
 *
 * This removes all previously added retimers under @port.
 */
void tb_retimer_remove_all(struct tb_port *port)
{
	struct usb4_port *usb4;

	usb4 = port->usb4;
	if (usb4)
		device_for_each_child_reverse(&usb4->dev, port,
					      remove_retimer);
}